A. A mouse equivalent to those in was dissected and its genital tract imaged ex vivo. The images are representative of data from at least 10 mice, and show either a standard photograph (Photo) or that photograph overlaid with the luciferase signal (Photo+Luc). The region with the highest signal was isolated and processed for histological analysis. The scale bar (photons sec−1 cm−2 steradian−1) shows the color scheme for signal intensity. Ov, ovary; UtH, uterine horn; Bd, body of the uterus; Cx, cervix; Vg, Vagina. B. The piece of vagina isolated in A. was fixed in formaldehyde and organ slices were either stained with hematoxylin-eosin (panels i to iii) or processed for immunohistochemistry with anti-MHV-68 rabbit polyserum (panels iv to vi) as described in the section. Rectangles indicate regions highlighted in the following panels. Arrows indicate focal recruitment of leukocytes at the periphery of MHV-68 antigen detection. Lu, lumen; SqEp, stratified squamous epithelium; LaPr, lamina propria; Mi, Muscularis; StCo, stratum corneum; StSp, stratum spinosum; Stba, stratum basale.